CVE-2023-5379 HIGH

CVE-2023-5379: Undertow: ajp request closes connection exceeding maxrequestsize

Vendor Red Hat
Product Red Hat build of Quarkus
Weakness CWE-770 · Uncontrolled resource consumption
Published December 12, 2023
Last update February 25, 2026

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

What the vulnerability does

01Description

A flaw was found in Undertow. When an AJP request is sent that exceeds the max-header-size attribute in ajp-listener, JBoss EAP is marked in an error state by mod_cluster in httpd, causing JBoss EAP to close the TCP connection without returning an AJP response. This happens because mod_proxy_cluster marks the JBoss EAP instance as an error worker when the TCP connection is closed from the backend after sending the AJP request without receiving an AJP response, and stops forwarding. This issue could allow a malicious user could to repeatedly send requests that exceed the max-header-size, causing a Denial of Service (DoS).

Key dates

02Disclosure timeline

December 12, 2023 CVE published
February 25, 2026 Record updated